1. Field of the Invention
The present invention pertains to a method for sealing unwanted portions of fractures in earth formations to minimize the production of water or other unwanted fluids while permitting the production of hydrocarbons or other desired fluids.
2. Background
In the production of hydrocarbons from wells extending into earth formations, a common practice to enhance production is hydraulic fracturing of the earth formation in a particular producing zone. Occasionally, hydraulic fractures will extend beyond the hydrocarbon-producing zone into water production zones, for example. This unwanted fracture growth or "out of zone fracture" can seriously affect the productivity of a well due to excess water production.
Accordingly, what is desired is to be able to seal or restrict water flow from only a portion of a hydraulic fracture or a similar fracture in the earth which extends between a hydrocarbon-producing zone and a water-producing zone. Although water flow control or permeability reducing compositions are known for injection into wells, known compositions and methods have not addressed the problem of sealing only a portion of a fracture while allowing fluids to be produced from a remaining portion of the fracture or a similar high permeability zone. It is to this end that the present invention has been developed with a view to providing an improved method for sealing unwanted fracture zones from those zones from which it is desired to produce certain fluids.